METHOD OF HOT-ROLLED PIPE PRODUCTION Russian patent published in 2013 - IPC B21B19/04 

FIELD: process engineering.

SUBSTANCE: proposed method comprises piercing the billet to rough tube, rough tube expanding, reeling and reducing. Decreased range of used rolling tools and production of tubes at tube-rolling units with reeling mills from 156 mm-dia continuously cast billet at lower costs and with higher quality is ensured by decreasing tube OD in reeling compared to that before reeling using simultaneous forming of tube wall with forming of tune in diameter in die convergent in direction of rolling. Note here that billet diameter is decreased at every step of hot processing.

EFFECT: higher efficiency of tube-rolling units, surface quality and precision of seamless hot-rolled tube.

2 dwg